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Quick pickled red onions

Name: Quick pickled red onions
Yield: one large onion’s worth of pickles
Ingredients: 1 large red onion, peeled and thinly sliced; 3/4 cup rice vinegar; 1/4 cup water; 1 teaspoon salt; 1–2 tablespoons sugar

Thin red-onion slices in a simple rice-vinegar pickle, ready after two hours in the fridge and useful for sandwiches and bowls.

By PickleRadio editorialUpdated 18 September 2026

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Fine pink pickled red-onion slices in a clear jar.

In this guide5 sections

A small topping that earns its fridge space

Yield: one large onion’s worth of pickles. Chill time: at least 2 hours.

These are the onions to make when dinner needs a sharp topping without another pan of food. A few drained strands work especially well with beans, melted cheese or roast potatoes. Slice them finely enough that a forkful contains onion and the food underneath, rather than one large, slippery ring.

This complete refrigerator formula comes from Utah State University’s Wasatch cooking-class handout. It uses rice vinegar, so choose an unseasoned bottle rather than a sweetened sushi seasoning. The onion recipe is on the second page of the handout.

Set up before measuring

Have a clean heatproof jar, a small saucepan and a spoon ready before slicing. Set the jar on a folded cloth so it is steady while you pour. Choose a container with room for the onion and liquid; this recipe is not sized as a canning batch.

Peeling over a bowl keeps the dry skins away from the prepared slices. Cut through the onion from root to tip, place each half flat on the board and take thin slices across it. Separate the layers before filling the jar.

Clean empty glass jars, a measuring jug and a small bowl of salt on a kitchen worktop.

Ingredients

1 large red onion, peeled and thinly sliced
3/4 cup rice vinegar
1/4 cup water
1 teaspoon salt
1–2 tablespoons sugar

Method

Put the sliced onion into the clean jar, separating any layers that cling together.
Separate the thin onion layers before putting them into the jar.
Combine the rice vinegar, water, salt and sugar in the saucepan.
Heat until the mixture starts to boil, stirring so the salt and sugar dissolve.
Stir until the salt and sugar dissolve and the liquid begins to boil.
Pour the liquid over the onion. Cover with the lid and refrigerate for at least 2 hours before eating.
Pour the hot liquid over the onion, then cover and refrigerate as directed.
Keep refrigerated and use within 2 weeks.

Choose the amount for the meal

Begin with the lower sugar amount if you want a sharper topping; both amounts are included in the published formula. Drain a forkful before putting it on toast so the bread does not become soaked. A little onion goes further if you scatter it across the surface instead of piling it in the centre.

Try it beside pickle quesadillas, letting diners add their own portion. For another jar with a different texture, browse the recipe collection. Keep this one refrigerated even if its lid appears sealed.